Daily handover in surgery: systematic review and a novel taxonomy of interventions and outcomes

Abstract Background Poor-quality handovers lead to adverse outcomes for patients; however, there is a lack of evidence to support safe surgical handovers. This systematic review aims to summarize the interventions available to improve end-of-shift surgical handover. A novel taxonomy of interventions and outcomes and a modified quality assessment tool are also described. Methods Ovid MEDLINE®, PubMed, Embase, and Cochrane databases were searched for articles up to April 2023. Comparative studies describing interventions for daily in-hospital surgical handovers between doctors were included. Studies were grouped according to their interventions and outcomes. Results In total, 6139 citations were retrieved, and 41 studies met the inclusion criteria. The total patient sample sizes in the control and intervention groups were 11 946 and 11 563 patients, respectively. Most studies were pre-/post-intervention cohort studies (92.7%), and most (73.2%) represented level V evidence. The mean quality assessment score was 53.4% (17.1). A taxonomy of handover interventions and outcomes was developed, with interventions including handover tools, process standardization measures, staff education, and the use of mnemonics. More than 25% of studies used a document as the only intervention. Overall, 55 discrete outcomes were assessed in four categories including process (n = 27), staff (n = 14), patient (n = 12) and system-level (n = 2) outcomes. Significant improvements were seen in 51.8%, 78.5%, 58.3% (n = 9761 versus 9312 patients) and 100% of these outcomes, respectively. Conclusions Most publications demonstrate that good-quality surgical handover improves outcomes and many interventions appear to be effective; however, studies are methodologically heterogeneous. These novel taxonomies and quality assessment tool will help standardize future studies.


Introduction
Communication failures in healthcare are common, contribute significantly to adverse patient events and errors 1,2 and cost an estimated $12 billion per year in U.S. hospitals 3 .An important communication event in the patient journey is the handover of care, which refers to 'the exchange between health professionals of information about a patient accompanying either a transfer of control over, or of responsibility for, the patient' 4 .
One-quarter of handovers are associated with handoverrelated care failures 5 , and there are 7.5 handover-related issues with patient care per 100 patient days in hospital, mostly arising from omissions of critical information 6 .Surgical patients are particularly at risk, seeing an average of 10 different doctors during a single admission 7 , with changing work practices requiring information handover even more frequently due to shift changes.Shorter hospital stays among surgical patients increase the intensity of care and volume of clinical information.In one month, surgical interns participate in an average of 300 handovers, and in three days, each surgical patient will be handed over an average of 15 times 8 .Handovers are costly when they are not performed well, with one study extrapolating cost savings of between £740 000 and £3.82 million in one hospital with an improved surgical handover process 9 .Malpractice claims associated with communication failures are significantly more expensive to defend, and 40% of these claims are due to failed handovers 10 .Errors during information transfer also lead to wasted staff time 11 and good-quality handover can reduce staff overtime 12 .The cost associated with this essential event to patients, staff and institutions means that an ad-hoc approach to handover improvement is not appropriate and changes should be supported by evidence.
Medical associations 13 , surgical colleges 14,15 and the World Health Organization 16 all offer guidance, but there is little evidence-based training for safe and effective surgical handover and no gold standard exists 15 .Handover interventions from other specialties are not always adaptable to the surgical ecosystem and are sometimes not rigorously evaluated prior to implementation 17 .In a review of articles published up to December 2013, only eight studies were found to address the daily surgical handover, with the majority focusing on the use of paper or electronic documents as interventions rather than overall process improvements 18 .Furthermore, the descriptions of methodologies employed were limited.The literature has increased significantly in the last 10 years; however, there is still little consensus on areas requiring further study.
The aim of this systematic review was to summarize and evaluate the literature on interventions used to improve the daily end-of-shift surgical handover.The authors sought to determine the types of interventions used, the outcome measures against which they were evaluated, and to assess the impact of interventions on outcome measures for surgical patients.Novel taxonomies have also been developed and reported for handover interventions and outcomes, and a modified quality assessment tool for handover research has been described.

Search strategy
This systematic review was prospectively registered on PROSPERO (CRD42022363198) and review methods were established prior to the conduct of this review.This review was also conducted in accordance with the PRISMA 19 and AMSTAR (Assessing the Methodological Quality of Systematic Reviews) Guidelines 20 .PubMed, PubMed Central, Embase and Cochrane databases were searched for all articles published from inception until April 2023 using a search strategy developed with an Information Specialist (full search terms are in Appendix S1).The results were combined into a reference manager database (Endnote X20, Clarivate PLC, Jersey).Duplicates were removed automatically and manually.The reference lists of the included studies, prior reviews of the same or similar topics and the trial registry Clinicaltrials.govwere screened for additional relevant studies.
Original studies were included if they utilized any intervention to improve daily handover between surgical doctors and reported any outcomes related to the surgical handover process.All interventional study designs were included due to the small number of RCTs available.During the full-text review, studies involving students and newly appointed doctors who had not yet entered clinical practice were excluded, as a review of educational handover interventions was previously performed 21 .The full inclusion and exclusion criteria are listed in Table 1.

Study screening and selection
Reviewers JR and FMcH independently applied inclusion and exclusion criteria to citations and abstracts to identify full texts for review.Full texts were then reviewed independently by both reviewers, with discrepancies agreed upon by consensus among the research team.

Data extraction
A template was created using Microsoft Excel (16.67, ©2022 Microsoft) and a subset of papers was allocated to two reviewers (JR and FMcH) for independent primary data extraction, with subsequent validation of all papers by the second reviewer.Any discrepancies were resolved by consensus with the wider research team.Where a study was described in limited detail, reviewers contacted the authors for further details.For each study, data on the study characteristics, interventions, controls, outcomes and results were extracted.

Data synthesis
Studies were first categorized according to the type of intervention used and then according to the outcomes assessed.A meta-analysis on this topic was not planned because of the high likelihood of clinical and methodological heterogeneity among the included studies 22 .

Quality assessment
The authors planned to use multiple quality assessment (QA) tools for the various study types; however, a literature review revealed that a tool specifically designed to assess handover research existed 23 , which was based on a checklist designed to assess studies of randomized and non-randomized healthcare interventions from Downs and Black [24][25][26] .
This handover QA tool was noted by the authors to omit key characteristics of study quality, including internal validity, quality of reporting and power calculations, leading to the design of a modified tool to address these deficiencies (Table S1).
Changes were based on the original checklist from Downs and Black 24 and more recent commentary on improvement 17,27 .Items that had initially been excluded 23 from the Downs and Black 24 checklist were assessed by the study team and re-inserted into the modified tool if they addressed the above omitted characteristics.Both versions of the handover QA tool were used for all included studies 9,12, and scores are reported in parallel. Two athors (FMcH and AS) independently performed QA for a subset of articles, while a third author (JR) reassessed and validated the QA scores for all articles.
Outcomes were compared, with any discrepancies agreed upon by consensus.

Development of intervention and outcome taxonomy
Categories of handover interventions were developed by the study team using deductive reasoning through a review of all included studies and previous similar reviews.For outcomes, the system described by Arora et al. 68 was updated to include an additional category.Outcome subcategories were then added through deductive reasoning by the study team, ensuring all outcomes included in the current study were represented.

Search results
In total, 42 papers were identified for inclusion in this review 9,12, . The 639 citations retrieved through database searches were screened and a full-text review was performed on 118 papers (Fig. 1).The results of an RCT were reported in two separate papers that were combined for the purpose of this review, leaving 41 studies for assessment 62,63 .There was 98.3% agreement between reviewers regarding papers for inclusion (Cohen's kappa = 0.96).

Quality assessment
The mean score using the previous QA tool 23

Handover intervention taxonomy
Four categories of handover interventions were developed, including the use of handover tools, process standardization measures, staff education, and the use of a mnemonic or memory aid.Each category includes subcategories; for example, handover tools can be classified as paper versus electronic, linked with the electronic patient record versus standalone 69 , and by degree of automation 69,70 (Fig. 2a, Table 2).

Handover outcome taxonomy
Outcome categories included patient, staff, process and system outcomes.Process outcomes are differentiated from patient, staff (workforce) or hospital (system) outcomes, recognizing that process improvement does not always correlate with changes in other domains.Each outcome category includes subcategories; for example, patient outcomes can be classified as those relating to care experience, avoidance of harm and clinical outcomes (Fig. 2b, Table 3).
Interventions included a formal face-to-face handover meeting (n = 6) 43,49,52,55,59,65 , handover policy (n = 5) 12,28,30,35,51 , increased supervision from senior staff (n = 1) 32 and the introduction of a process to highlight high-risk patients (n = 3) 9,39,65 .Most studies implementing a new handover meeting demonstrated significant improvements in at least one area, including reduced length of hospital or ICU stay (n = 3 and n = 1, respectively) 43,52,59 , although increased weekend discharges (n = 1) 43 , reduced emergency calls (n = 1) 43 , appropriate escalations of care (n = 1) 49 and increased reporting of adverse events (n = 1) 65 were also noted.Introducing a process to identify high-risk patients led to improvements in all studies in which it was tested.One study combined this with a standardized paper handover template and reported a reduction in the average length of stay (LOS) for emergency patients of 1.9 days (P = 0.03), increased average weekend discharges (39.1 to 48.9; P = 0.003) and putative cost-savings 9 .Another study saw a 147% increase in reporting of adverse events (P = 0.007) when a 'red flag' system was combined with a new handover meeting 65 .A 'traffic light system', supported by staff education and a handover document, reduced ward round duration by 30 min, increased weekend discharges and improved documentation availability and staff confidence (P values not reported) 39 .Additionally, increased senior supervision and education increased handover occurrence (P < 0.05) and reduced the number of patients with inadequate investigations and treatment (P values not reported; calculated by reviewers as P < 0.05 and P < 0.001, respectively) 32 .
No study used a validated questionnaire, although one developed questions through a representative Delphi process 37 and another was based on national handover guidelines 28 .With various handover interventions, significant improvements were seen in handover performance 36 , staff overtime 12 , staff perception of handover quality 58,60,64 , staff satisfaction 67 , perceived handover safety 58 , perceived process efficiency 58 , perceived service coordination impact 31 , perceived ward round efficiency 44 , perceived information governance 44 , staff knowledge of patients 47 and clarity of transfer of responsibility (Table S5).

System outcomes
Weekend discharges were evaluated in three studies, two of which demonstrated significant improvement 9,43 and one that reported improvement without P values (5% versus 20%) 39 .One study extrapolated cost savings of £740 000 and £3.82 million arising from a reduced LOS after the introduction of a handover intervention 9 .

Discussion
Of the 6139 screened citations, 41 studies of 23 509 patients were identified, which evaluated the impact of four categories of handover interventions on 55 discrete outcomes.Interventions were mostly tool-based (82.9%), with mixed interventions being common (63.4%).Outcomes were widely heterogeneous and rigorously evaluated in a minority of studies, with only two RCTs 36,62,63 and one case-control study 61 .Even by the standards of earlier, less-rigorous QA tools, more than half of the studies met fewer than 65% of quality metrics.A novel taxonomy for the interventions and outcomes used in handover research was developed and the existing handover research QA tool was revised to increase its rigor.As expected, a meta-analysis was  not possible because of the clinical and methodological heterogeneity between studies 22 .Multiple varying taxonomies of handover interventions and outcomes have been described previously 18,69,70,71 .These variations reflect the heterogeneity of the literature and lack of methodological guidance for handover research.Novel taxonomies for handover research interventions and outcomes were developed, which will help reduce heterogeneity in future research.
A modified methodological tool for assessing the quality of handover research is also reported in this paper.The original tool omitted items relating to internal validity, quality of reporting and power calculations 23 and the modified tool better differentiated high-from low-quality studies.Quality scores have not improved since the last systematic review on this topic 10 years ago 18 , despite a large increase in studies.However, the standard of surgical handover research is comparable to healthcare handover research generally, which has a median score of 9-10 23,70,72 .The use of the modified tool will support better-quality future research in all areas of handover research beyond the discipline of surgery alone.
Handover tools, specifically documents, were the most common interventions, and electronic documents were often associated with process outcomes, including improvements in written handover content and some patient outcomes.One-quarter of all papers used a handover document as the only intervention, the majority of which (63.6%) were published within the last 10 years.A handover involves information transfer about a patient from one doctor to another 4 , but more importantly requires two-way communication 73 , which cannot be guaranteed with a simple document.Automation has not been adequately tested here, with a minority of electronic tools utilizing it 28,31,48,58,62,63,[65][66][67] .Manual updating of a tool hampered handover in multiple studies 70 and can contribute significantly to written errors 74 .Facilitating automation in future studies would reduce wasted effort and improve staff experience.While staff education was utilized in most studies 28- 30,32-37,39,40,42-44,47,51,53-56,60-63,65,67 , interventions were poorly described, with only one study reporting methodology to a replicable degree 61 .Surgical handover curricula would benefit from increased research in educational interventions.
Regarding process standardization, both the introduction of a handover meeting and a method to highlight unwell patients demonstrated improvements.The I-PASS handover bundle specifically requires that illness severity is highlighted at the beginning of each patient presentation and significantly reduces preventable adverse events 75 .Drawing the listener's attention to the sickest patients on the list should be a vital component of any future interventions.
Surgical handover interventions led to significant improvements in 58.3% of patient outcomes.Cohen and Hilligoss (2010) describe handover practices as deeply embedded in local culture and remark that staff are unlikely to change their behaviour unless they see concrete improvements in patient outcomes 4 .Focusing on patient outcomes in future studies is worthwhile; however, measurement is laborious, time-consuming, and often requires funding.Starmer et al. required two research nurses for 5 days/week to identify a reduction in preventable adverse events 75 .In the current review, seven studies assessed adverse events 29,42,52,58,60,61,63 but only one demonstrated improvement 58 .Only one study performed a power calculation 63 and data collection methods were variable.Despite the relatively high number of studies evaluating this outcome, a reduction in adverse events with an improved study design cannot be reliably predicted.In addition to adverse events, LOS and ward round reviews appear to be key outcomes for assessment in handover research.
The rate of funded handover research (2.4%) is much lower in surgery than in healthcare overall (15-28.6%) 69,72.Funded studies receive higher QA scores 72,76 , as reflected in this review 42 .Poorly conducted handovers are expensive in terms of opportunity costs associated with inefficient processes, wasted staff time and adverse events.Surprisingly, no studies included any form of cost/benefit analysis, workforce cost implications, or evaluation of the impact of handover related to risk management or medicolegal claims.The monetary cost of communication failures 3 and potential cost savings of handover interventions 9 speak to the potential return on investment in funding higher-quality handover research.
The main limitation of this review is the poor quality of available data.Most studies are level V evidence; even when assessed using tools that accept the limitations inherent in handover research, quality scores remain low.Only one study performed a power calculation 62,63 , 43.9% did not perform significance testing for at least one outcome 12,28,30,32,33,35,37- 40,42,45,48,51,53,55,56,58 and 21.9% did not report at least one sample size 9,30,33,45,47,55,58,65,67 .The existing QA tool for handover research was updated to incorporate key tenets in assessing research quality in order to more accurately distinguish between high-and low-quality studies, and to raise standards for future research.
The universal lack of accepted outcome measures for handover research has led to a wide variety of interventions and outcomes being used, including 11 different combinations of interventions and 9 different combinations of outcomes.As such, it was not possible to directly compare many of the studies, and the subject was not suitable for meta-analysis.Prioritization of interventions and outcomes for handover research, through the development of a core outcome set, would minimize variation in the future.In addition, the subject area would benefit from specific reporting guidelines.
Despite the implications of daily surgical handover in terms of patient safety, staff workflow and hospital expenditure, a body of supportive interventional research has yet to be established.It is important to mitigate the risks associated with handover through process improvements.However, unplanned disruption of existing workflow patterns may increase harm; therefore, it is necessary to demonstrate that new approaches both improve patient safety and deliver value to the health system.At present, effective interventions appear to include implementing a formal face-to-face handover meeting, an automated electronic handover document listing patient details, a method to highlight critically unwell patients, ensuring appropriate senior supervision, staff education and the use of a mnemonic or memory aid to structure patient presentations.Future studies should prioritize these interventions and their effect on patient outcomes, particularly adverse events, ward round reviews and length of stay.The novel taxonomies described here also provide a new language with which to describe handover research and create uniformity in future research studies.

Table 2 Intervention definitions and studies utilizing each intervention category
Values are n (%).EPR, electronic patient record; I-PASS, Illness severity, Patient summary, Action list, Situation awareness & contingency planning, Synthesis by receiver; SBAR, Situation, Background, Assessment, Recommendation; ABCD, Airway, Breathing, Circulation, Disability.